not really that rough. he gives you the main tropen, i.e., the higher mafsikim, and with a bit of knowledge concerning trop it isn't difficult to fill in the rest of the trop.keep in mind that the system for trop symbols (and nikkud in general) was originally much more simple than what we have today. this mishnah text represents--intentionally or not i don't know--an earlier period when mss. contained a simplified trop in general, and sometimes lacked mesharesim altogether (as does the present text and as did iirc babylonian texts?)

curiously in this mishnah text there is no siluk and he seems to use the esnachta for this purpose?

there are a number of examples of mishnah fragments with nikkud from the cairo (and leningrad?) geniza.

I just saw in kovetz igros from rav Gifter (just added to Hebrewbooks) pg 47 where he writes exactly this, that he saw in one of the kadmonim that the gemorrah in megilla שונה בלא זמרה means that they had trup in mishnayos, but he forgot where he saw it.